2177 search results for "twitter"

Statistical analyses using R

April 22, 2011
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Statistical analyses using R

Another book I received from the Short Book Reviews section of the International Statistical Review is Everitt’s and Hothorn’s Handbook of statistical analyses using R. Here is a version of my book review. This book is the second (blue) edition of a successful (violet) handbook that can benefit a wide audience interested in using

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Sexy, Geeky Graphs using ggplot2 in R

April 22, 2011
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Sexy, Geeky Graphs using ggplot2 in R

So I’ve been looking for some data to play with while learning R, other than the data I’m analysing for various experiments and papers I’m working on. I thought to myself, “Hey, this R stuff is pretty geeky. Can I engage in a higher level of geekiness?” And I think I’ve found a way: using

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Lack of confidence [revised]

April 21, 2011
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Lack of confidence [revised]

Following the comments on our earlier submission to PNAS, we have written (and re-arXived) a revised version where we try to spell out (better) the distinction between ABC point (and confidence) estimation and ABC model choice, namely that the problem was at another level for Bayesian model choice (using posterior probabilities). When doing point estimation

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stalkR: R functions for exploring iPhone and iPad (OS X only)

April 21, 2011
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stalkR: R functions for exploring iPhone and iPad (OS X only)

Yesterday Alasdair Allan and Pete Warden shocked the world by revealing that iPhones and iPads have been keeping track of our every move, and saving the data in obfuscated back up files. As my friend Vince Buffalo mentioned on Twitter, part of me was disgusted by the secret stalking Steve Jobs was doing, but my

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Thomas Bayes, 250 years later

April 21, 2011
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Thomas Bayes, 250 years later

A link on R-bloggers signaled a series of blogs and videos by IBM Netezza about Thomas Bayes and the consequences of his theorem. Which made me realise this was indeed the 250th anniversary of his death, and that maybe we (as a collective, incl. ISBA) should have done something on April 17th… Before the Revolution

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New R User Group in Gießen, Germany

April 21, 2011
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It's great to see new local R user groups popping up around the world, and the latest one is based in Gießen, Germany (about 70km north of Frankfurt). The Giessen R Users Group has its first meeting on May 10 with a discussion on applications of R to social media (with an example related to Twitter). meetup.com: Giessen R...

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(Almost) Friday Function: alarm

April 21, 2011
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(Almost) Friday Function: alarm

Last week I decided to start a weekly column detailing an interesting function each Friday, entirely forgetting that I would be on holiday, without internet access (shock horror!), tomorrow. So here’s your column a little early. The alarm function is something of a novelty, in that all it does is to make an annoying noise

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supercalifragilisticexpialidocious = 1

April 21, 2011
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supercalifragilisticexpialidocious = 1

I notice that the latest version of R has upped the maximum length of variable names from 256 characters to a whopping 10 000! (See ?name.) It makes the 63 character limit in MATLAB look rather pitiful by comparison. Come on MathWorks! Let’s have the ability to be stupidly verbose in our variable naming! Tagged:

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Non-standard assignment with getSymbols

April 21, 2011
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Non-standard assignment with getSymbols

I recently came across a rather interesting investment blog, Timely Portfolio. I have a certain soft spot for that sort of thing, because using my data analysis skills to make a fortune is casually on my to-do list. This blog makes regular use of a function getSymbols in the quantmod package. The power and simplicity

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ARMA Models for Trading, Part II

April 20, 2011
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ARMA Models for Trading, Part II

We left the last post at the point of determining the best ARMA model. Before continuing the discussion, however, I would like to make a few points that might seem a bit questionable or unclear: We model the daily returns instead of the prices. There are multiples reasons: this way financial series usually become stationary,

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